Tube material, such as T/E (Tamper Evident) tube stock, is rolled and stocked prior to use. This rolling and stocking causes the tube material to be flattened and for its inner surfaces to bond to each other; therefore, it is necessary to separate the bonded surfaces of the flattened material from each other in order to put the tube material in practical use. For opening such tube material, an opening wedge positioned within the tube material is generally used.
As the tube material travels in a longitudinal direction, the tube material is automatically opened by the wedge. Typically, the opening wedge is located between two pairs of parallel rollers which are mounted at upstream and downstream ends of the tube material. The rollers guide the tube material as it travels between them.
Some conventional wedges are made of solid metal or plastic. Others are made of sheet metal shaped and welded to form a shell. Still other conventional opening wedges are made of solid plastic with spring loaded wings or of metal rods formed into a frame. Some conventional opening wedges are adjustable and/or spring loaded.
However, there are disadvantages with conventional opening wedges. One disadvantage is that surface contact between the opening wedge and tube material causes unacceptable friction between them. This results in static electricity which prevents the layers of tube material from separating from each other easily.
Also, with conventional opening wedges, the tube material may jam between the opening wedge and the parallel rollers, because the opening wedge is forced into the downstream parallel rollers with the tube material due to friction.
Accordingly, an object of the present invention is to provide an apparatus for opening tube material in which friction between the apparatus and the tube material is reduced.
Another object of the invention is to provide an apparatus for opening tube material in which the incidence of jamming is reduced.
Additional objects, advantages and novel features of the present invention will become apparent to those skilled in the art from this disclosure, including the following detail description, as well as by practice of the invention. While the invention is described below with reference to preferred embodiments, it should be understood that the invention is not limited thereto. Those of ordinary skill in the art having access to the teachings herein will recognize additional applications, modifications and embodiments in other fields, which are within the scope of the invention as disclosed and claimed herein and with respect to which the invention could be of significant utility.